How to place text behind object in image?

I'm using Adobe InDesign to produce a magazine. I use Photoshop CS too. Usually the cover is a simple single photo over which is pasted the magazine masthead twice - once each in a different color to create a drop shadow effect. Occasionally I would like to put the masthead behind an object in the image ... so the cover has a sort of 3D feel.

For example a group of toy balloons in a blue sky. I'd like the masthead to be in the sky but behind the bunch of balloons. It seems simple but for the life of me I can't get it.

Can someone help or point me to a simple step-by-step tutorial on how to do this?

You could apply a layer mask,and brush away the area you want to appear hidden.

Here's a suggestion that works for indesign or photoshop...(in principle):

Duplicate the background image and paste it over and under the masthead like a sandwich, in EXACTLY the same position and delete part of the front image. Because the 2 graphics are exactly aligned, you can chop the front image as you like.

In your example, select the balloons, apply a 1 pixel feather, invert the selection and delete to transparent.

Make sure you view in high quality performance mode in InDesign to see the proper result.

If you assemble it in InDesign, it is best not to work on the background layer in photoshop or you will have trouble deleting to transparent.